1. Field of the Invention
The present invention relates to an optical communication module and a method for using the same intended to eliminate a tangle in optical fiber interconnection and to reduce the amount of an optical fiber used for interconnection.
2. Related Art
An optical communication module (which is also called an optical transceiver) incorporating an optical package for optical communication and its peripheral circuit in a housing includes: an optical transmitter module in which a light-emitting element as a semiconductor optical device is incorporated in the optical package and the peripheral circuit in the optical package is a light-producing driver circuit; an optical receiver module in which a light receiving element as a semiconductor optical device is incorporated therein and the peripheral circuit in the optical package is a first-stage amplifier circuit; and an optical transmitter and receiver module in which elements and circuits both for light-emitting and light receiving are incorporated. Since the optical communication modules are not so different in optical structure from each other, the optical transmitter module will be described as an example below.
An optical communication module is used being mounted on an optical communication board disposed in a housing of a fixed communication device. Therefore, the optical communication module is provided with an electrical connector exposed at the bottom surface of the housing.
An example of related art to the invention is disclosed in Japanese patent No. 3134850 (equivalent to JP-A-11-149004).
The optical communication board has plural electrical connectors in order to mount plural optical communication modules thereon. In increasing an optical communication channel, one optical communication module only has to be inserted into one electrical connector. However, at least one optical fiber 122 is necessary for one optical communication module 121. Thus, as shown in FIG. 12, one optical fiber 122 must be added when adding one optical communication module 121 such that plural optical fibers 122 are arranged on an optical communication board 123. Although the plural optical fibers 122 are shown in orderly arrangement in FIG. 12, it is impossible to arrange them orderly, and, in fact, the optical fibers 122 will be tangled. Needless to say, the optical fibers 122 will be also tangled outside the communication device.
Furthermore, the optical fiber 122 is interconnected between the communication device for housing the optical communication board 123 and an optical communication board of a nearby communication device, where the interconnection distance is generally several meters to several tens of meters. Since the amount of the optical fiber needed can be calculated by (the number of fibers)×(interconnection distance), the amount of the optical fiber used increases every time the optical communication channel is added.